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Hello,
during a course project studying security and privacy related to
Bluetooth, we discovered a simple but effective DoS attack using OBEX push.
Using ussp-push [1], it is possible to send out files very quickly. By
continuously trying to push a =EF=AC=81le, the target is =EF=AC=82ooded with prompts
whether to accept the =EF=AC=81le or not, which disables any other usage on the
phone, including the ability to turn off Bluetooth.
We confirmed the attack to work on the following phones:
- Sony Ericsson K700i
- Nokia N70
- Motorola MOTORAZR V3
- Sony Ericsson W810i
- LG Chocolate KG800
and expect nearly all available phones with Bluetooth to be vulnerable
(in contrary to the previous DoS by l2ping).
A proof-of-concept code is attached (plain text), using ussp-push and
targeting a known MAC. This could be easily extended to target all
visible devices.
Plus, a user could be forced to accept a possibly malicious file with
this attack. Using only one Bluetooth-Dongle, we were able to
practically disable three phones simlutaneously.
Best regards,
Stefan Ekerfelt and Armin Hornung
[1] http://www.xmailserver.org/ussp-push.html
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